1. Field of the Invention
This invention relates to novel compositions of matter. More particularly it relates to a composition of matter having the formula: ##STR2## or mixtures thereof, wherein R.sub.1 and R.sub.2 are C.sub.1-20 hydrocarbyl groups, as defined below, which may be the same or different, or one of R.sub.1 and R.sub.2 may be hydrogen, and R.sub.3 and R.sub.4 are methyl or hydrogen, and may be the same or different, which compositions are useful as insecticides. This invention also relates to the method of preparation of these polymethylmuconic acid derivative compounds as hereinabove defined.
2. Description of the Prior Art
It is well known that certain organothiophosphates have insecticide properties. The most widely used is Parathion (O,O-diethyl O-p-nitrophenyl thiophosphate) which is effective against a wider variety of insects than any known insecticide. However, it has a relatively short residual action and it is extremely toxic to humans. Malathion (O,O-dimethyl S-(1,2-dicarbethoxyethyl) dithiophosphate is less toxic to humans but hydrolyzes and isomerizes more easily, and therefore is less stable both in storage and as an insecticide residue. Thus, there exists a need for an effective insecticide agent that is not toxic to humans, yet is more persistant, i.e. remains on the treated area longer.